Grain boundaries (GBs) in metals are commonly seen as preferential sites for crack nucleation and propagation. It has been shown that the atomic arrangements at GBs can affect the crack propagation [J. J. Möller, E. Bitzek, Acta Mat., 73, 2014, 1]. The atomic arrangement, in turn, depends on the misorientation, the GB plane, but also on GB defects like ledges and consequently on GB curvature.

Here we present the results of atomistic fracture simulations along tilt GBs in Tungsten. Crack propagation was studied for planar GBs of identical misorientation but different plane normals, as well as for curved GBs containing locally the same GB planes. Crack propagation for different GB misorientations were also investigated. In addition to quasi 2D simulations with minimal crack front length, simulations of extended crack fronts interacting with localized GB protrusions were performed. The results are discussed in terms of the plane-dependent GB energy, fracture surface area and the local stress state at GB defects.